The present invention relates to an improved device for activating and measuring a nonflowing producing well and notably a deflected well, this term standing for any well at least part of which shows a more or less strong inclination in relation to the vertical and/or substantially horizontal parts.
Different procedures of an activating and logging device for wells equipped for production, of the nonflowing type, and notably for deflected wells, are described in French patent applications 2,637,939 and EN. 89/04,225. The described devices are particularly suited to wells equipped for producing oil effluents. They allow determination of the most favorable well portions when the wells cross heterogeneous reservoirs producing oil, but also water and gas. The equipment of a well generally comprises a casing that is kept in position by cementing. A liner perforated at least on part of the length thereof which continues the casing is arranged in the total zone intended for production. This perforated liner can be possibly cemented, the cemented annulus being provided with passageways which link the producing zone with the liner. A flow string built up by connecting successive sections is lowered into the liner. The flow string is provided with parts for centering the string with respect to the liner Sealing means are arranged in the annular space between the string and the liner in order to canalize in the string the total effluents produced by the producing zone. The well being nonflowing, activating or pumping means are associated with the string and lowered into the well to draw the effluents. These activating means comprise, for example, a pump rotatably driven by an electric or hydraulic motor.
The device comprises at least one assembly of measuring instruments at the base of the flow string to measure the characteristics or properties of a portion of the fluids drawn by the pump. Isolating means are arranged around the string in order to separate the liner into two parts and to limit the measurements carried out to the effluents coming from only one of these two parts. The device can also comprise two measuring assemblies to separately measure the characteristics or properties of the fluids coming from the two opposite parts of the liner. The logging device is displaced by lengthening or shortening the string in order to carry out measurements on the effluents flowing out of the formation in various locations of the well.
French patent application EN. 90/03,305 describes an improved logging device for more precisely determining the features of the multiphase flows from a producing well, with the improvement being essentially due to the use of means for homogenizing the effluents prior to treatment by the measuring instruments.
In all the patent applications cited above, the activating pump and the driving motor thereof are arranged at the base of the string at a position near the measuring instrument assemblies. It has been experienced that this layout was not suitable for many producing wells. The section of the activating pumps and of the driving motors which are commonly used is actually relatively large and, in certain cases, the previous activating and measuring devices could not be lowered into certain producing wells whose section is smaller than the standard sections. Additionally, supplying the downhole motors is carried out through electric cables most often arranged in the annular space between the liner and the flow string. In the deflected parts of the producing wells, experience has shown that this supplying mode may show some failures due to a possible crushing of the feeder cables.